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| author | Dave Martin <dave.martin@linaro.org> | 2013-02-13 16:20:44 +0000 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2013-09-23 18:47:31 -0400 |
| commit | d08e2e09042bd3f7ef66a35cb4bb92794ab26bb2 (patch) | |
| tree | e34b0ae05a946887e11432db8f09d0110c9d6077 /arch/arm/common | |
| parent | 29064b88466ee725613db16d8c05b0ec5443a309 (diff) | |
| download | linux-d08e2e09042bd3f7ef66a35cb4bb92794ab26bb2.tar.bz2 | |
ARM: bL_switcher: Add query interface to discover CPU affinities
When the switcher is active, there is no straightforward way to
figure out which logical CPU a given physical CPU maps to.
This patch provides a function
bL_switcher_get_logical_index(mpidr), which is analogous to
get_logical_index().
This function returns the logical CPU on which the specified
physical CPU is grouped (or -EINVAL if unknown).
If the switcher is inactive or not present, -EUNATCH is returned instead.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'arch/arm/common')
| -rw-r--r-- | arch/arm/common/bL_switcher.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c index f4878a36047a..63bbc4f70564 100644 --- a/arch/arm/common/bL_switcher.c +++ b/arch/arm/common/bL_switcher.c @@ -532,6 +532,26 @@ static int bL_switcher_halve_cpus(void) return 0; } +/* Determine the logical CPU a given physical CPU is grouped on. */ +int bL_switcher_get_logical_index(u32 mpidr) +{ + int cpu; + + if (!bL_switcher_active) + return -EUNATCH; + + mpidr &= MPIDR_HWID_BITMASK; + for_each_online_cpu(cpu) { + int pairing = bL_switcher_cpu_pairing[cpu]; + if (pairing == -1) + continue; + if ((mpidr == cpu_logical_map(cpu)) || + (mpidr == cpu_logical_map(pairing))) + return cpu; + } + return -EINVAL; +} + static void bL_switcher_trace_trigger_cpu(void *__always_unused info) { trace_cpu_migrate_current(get_ns(), read_mpidr()); |